Coined wire splice



May 8, 1945. M LEE 2,375,480

COINED WIRE SPLICEL Filed- Dec. 29, 1941 44 4 1' 27 Anim GJ FI6.4-

FIG .7' M4RV/N LEE v mvawom B'Y gymm rmg Patented May 8, 1945 COINED WIRE SPLICE Marvin Lee, Rye, N. Y., assignor to B irndy Engineering Company, Inc., a corporation of New York Application December 29, 1941, Serial No. 424,753

3 Claims.

My invention relates to electrical connectors and more particularly to means for splicing a conductor to a metal sleeve.

The principle object of my invention is to provile a simple and inexpensive means for securing a conductor under tension, to a copper sleeve. I accomplish this object of my invention by providing 'cylindrically shaped punches which are driven into the wall of the sleeve with the condu-ctor inserted therein, thereby coiningthe metal of the sleeve into the wall of the conductor without damaging the conductor and keying the conductor to the sleeve without materially altering the normal tensile strength of the conductor.

Other objects of my invention are to provide an inexpensive method of applying the punches to the copper sleeve; to provide means for regulating the depth of the punch so as not to entirely penetrate the wall of the sleeve; to provide punches of varying heights and diameters so as to damage the conductor least where it joins the sleeve; to provide punches that drive the metal radially before it so as to permit the punches to be positioned close together; to cause dome shaped bulges to be keyed into the conductor; to provide punches which may be permanently set in the connector wall; and to provide punches which do not deform the outer surface of the connector adjacent the hole produced by the punch. 1

I accomplish these and other objects and obtain my new results as will be apparent from the device described in the following specification, particularly pointed out in the attached claims, and illustrated in the accompanying drawing, in which:

Fig. 1 is a front view of the head of a compressing tool with connector splice positioned therein ready for the punching operation.

Fig. 2 is-a side view of the same.

Fig. 3 is a partially sectioned longitudinal view of my connector splice.

Fig. 4 is an exaggerated side view of a set of punches with varying heights and diameters mounted on a base.

Fig. 5 illustrates a punch with a concave end.

Fig. 6 is a partially sectioned longitudinal view of my connector with pre-set permanently retained punches.

Fig. 7 illustrates a connector terminal with pre-set punches applied thereto.

Referring more particularly to the drawing,

sleeve having a bore H slightly in excess :of the diameter of the conductors 20 and 21.

In Figures 1 and 2, a hydraulic press 30 is shown for driving a portion of the wall M of the copper sleeve into the conductors. It consists of the U-shaped head 3| provided with a connector supporting socket 32, and a ram 33 which actuates the punches 40, mounted on the base 34.

Where a splice type of connector is employed forjoining two conductors 2'0, and 2|, as is illustrated in Figs. 1 and 3, a central peripheral groove or an indentation I5 is formed into the outside of the connector wall, causing an inner ridge or protrusion IE to extend into the bore which is used as a stop for the conductors when inserted into the splice.

The conductors 2'0 and 2'! are inserted into the sleeve Ill, until they reach the stop H5. The hydraulic press 30 is then applied to the sleeve through the mouth 35 of the U-shaped head. It is properly spaced on the sleeve so that the punches '40 Will enter the wall of the sleeve directly below the conductors.

The cylindrically shaped punches Ml are designed to drive the metal of the sleeve Ill, radially before it and result in dome-shaped bulges ll appearing on the inner surface of the connector and in the conductor therein, thus keying in the conductor to the sleeve. By not causing the metal to be forced transversely to the direction height and smallest diameter.

of the punch, smaller diameter punches may be used to produce a given bulge, and the punches may be positioned closer together without damage. Thus a greater number of longitudinally spaced bulges may be produced which injures the conductor least, and results in greater pull-out values over all other types. The punches operate more efliciently if the diameter of the punch is less than the distance the punch is driven into the metal. The punches are driven in a sufiicient distance without breaking the inner surface of the connector.

The punches may be flat headed, as at 4|, shown in Figures land 2, or concave as at 42 shown in Fig. 5. The punches may be progressively varied in height and diameter as for example with the central punches 43 having the maximum height and/or diameter as shown in Fig. 4, and the end punches 44 having the least This will damage the conductor least near the ends of the sleeve, an important consideration, and also make impossible reversing the position of the large and small size punches with respect to the end of the sleeve.

A satisfactory arrangement is to have the punches all the same size and arran ed to produce a longitudinal line of indentations of the same depth on the connector. However, this may be varied in many ways. The punches may be arranged so that two diametrically opposite rows of indentations are produced. The individual indentations may be diametrically opposite or may be staggered.

An alternative design of the connector is obtained by making the punches a permanent part of the connector instead of part of the press. In the manufacture of the connector, short cylinders 5B, of hard metal are inserted into the tubing wall (ill a predetermined distance with sufficient length projecting out of the tubing wall to provide the driving distance, as shown in Fig. 6. Thecylinders may be inserted in drilled holes, or forced in over a mandrel, not shown. Pressure is thereafter applied with a suitable tool to force these cylinders into the tubing and the conductors, until their ends are substantially flush With the outside tubing surface. The action in this case is substantially the same as in the previous case and the same variations of size of the cylinders may be made as in the case of the tool applied punches.

The two types of gripping devices described above may be employed in various forms of connectors in addition to the straight connectors shown in Figures 1 and 3. For example, they may be used for terminals 70 as shown with terminal plate 12, aperture 13, tubular body 14, preset punches i5. and conductor 16.

An advantage of the invention is that the contour of the sleeve remains substantially unaltered after the application of the pressure applying tool and dies. By use of the preferred form of punches, a longitudinal group of them may be positioned closely together without interference with each other and produce a keying action on the conductor that does not materially alter its normal tensile strength. The punches are inexpensive to apply, the hydraulic press being used for many types of additional purposes, and being capable of adjustment to regulate the depth of the punch. The connector may be designed with pre-set punches requiring a simple tool in the field to drive them flush. I have further found that a plurality of small holes are easier to make than one large hole of equivalent cross-section, injure the conductor least, and give better tensile pull-out values. I

I have thus described my invention, but I desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of my invention, and, therefore, I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of my invention are attained and new results accomplished. as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

What I claim and desire to secure by Letters Patent, is as follows:

1. A connector having a tubular body for accommodating a conductor inserted therein, and having a plurality of portions of the tubular body forming a row along the longitudinal axis of the tubular body, said portions having a uniform cross-section radially coined into the conductor, with the portion nearest the tubular end wherein the connector is inserted, less in height than the remaining portions.

2. A connector comprising a tubular body for accommodating a wire therein, said tubular body having a recess in the wall of the tubular body of uniform cross-section and radially positioned with respect thereto, and a piece of metal posh tioned in said recess of uniform cross-section, said piece of metal being adapted to be driven into the remainder of the tubular wall, forcin the metal radially before it, when the wire is inserted into the tubular body.

3. An electrical connection comprising a smooth surfaced conductor and a tubular sleeve having a smooth surfaced bore, the wall of the tubular sleeve having a partially sheared portion thereof, radially driven into the conductor to form a keying-in-section for resisting the pull-out of the conductor.

MARVIN LEE. 

